I had this happen too. What worked for me was I turned off the Rovio, plugged in USB turned on Rovio until the computer saw it as a drive that needed to be formated (repeated this many times). Once you see it as a drive, unplug USB (DO NOT turn of Rovio) and plug back in and run setup software.
Good luck, hope it works for you.
Let us know if it does.
PLEASE LET ME BE A BETA TESTER!!!